Weighted Trunk Twists
This exercise is only suitable for Intermediate or Advanced persons, with the dificulty of the exercise being heavily determined by the weight being used.
Lie centrally on the Bosu, holding a suitable single dumbbell with both hands.
Exhale and raise up to an almost seated position, the closer to a 90 degree angle you make, the easier the exercise becomes.
Once in this position, rotate from your trunk, taking your arms and upper body around to one side, then the other. Focus on a smooth action, rather than forcing your body or the weight around.
Inhale as your lower back down under control, repeating the movement, for desired number of repetitions.